Acoustical treatment of walls



APT 27 1937- R. F. NoRRls COUSTICAL TREATMENT OF WALLS original Filed Dec. e, 1935 @Mu/w55:

" QM '8W CII Patented Apr. 27, i937 UNITED STATES PATENT OFFICEl AooUsTIcAL TREATMENT or WALLS Ralph Forbush Norris, Madison, Wis., assignor to C. F. Burgess Laboratories, Inc., Chicago, Ill., a corporation of Delaware 11 Claims.

I'his invention relates to the acoustical treatment of walls which are subjected to sound vibrations and other vibrations, such as the walls of airplane cabins, and relates particularly to vibration dampening mountings for the windows which are located in such Walls. This application is a division of my co-pending application Serial No. 53,277, led December 6, 1935. That application relates to a treatment which is applied to the walls for the purpose of preventing the transmission of vibrations therethrough. 'Ihis application relates to the mounting of the windows in such walls and to preventing the transmission of the vibration of the walls to the windows.

It has been found that a treatment of the walls may not be completely effective, and a disturbing proportion of the vibrations may be transmitted to the cabin interior, unless the windows are provided with vibration dampening mountngs.

The relatively heavy glass windows may cause the sections of the walls'surrounding them to act as diaphragms weighted at the centers and may cause an actual increase in the vibratory action of the walls unless cushioning mountings are provided.

'I'he object of the invention is to provide improved vibration dampening'mountings for the windows so as to overcome the difliculties just enumerated.

In the drawing:

Fig. 1 is a fragmental side View of the framework and exterior wall of an airplane having the Window mountings of this invention;

Fig. 2 is a fragmental sectional View of one form of the window supporting means of this invention; and

Fig. 3 is a similar view of amodi'ed form of window supporting means.

The frame-work 9 of the airplane has an eX- terior wall or skin I composed of thin, lightweight sheet metal, suitably fastened to it. The windows II are arranged in the wall I0, and in the supporting means shown in Fig. 2 a bracket I2 is attached to the wall along the edges of the window opening. Although it is immaterial whether the bracket is located on the outside or inside of the wall I0, for purposes of description it is positioned on the inner side. The bracket and the wall edge are shaped to form a clamp and a channel for`the exible, preferably soft rubber, glass supporting strip or seat I3. The narrow clamping space I4 receives the projecting edge l5 of said rubber seat and the wider channel space I6 between the outwardly flared marginal portions I'I of the wall and bracket receives the hollow, substantially tubular portion I8 thereof. The supporting strip as a whole is secured by means of the clamping engagement described, and the hollow enlarged portion is not cemented or otherwise attached to the channel walls I1. The outwardly opening slot I9 receives the edge of window pane Il, which may be cemented in place. Similar construction may be employed at all edges of the window. The window casing 20 is clamped against bracket I2 and holds in position the edge portions of the decorative interior lining 2I of the cabin which surrounds the window opening.

The window mounting described is an effective vibration dampening means because of the great exibility of the thin walls of the hollow portion I8. Inward movement of wall IU causes a com-v pressive force upon exterior Wall portion 22 of the rubber mounting, which is transmitted to the glass panel weakly at rst but more strongly as exterior channel portion I'I approaches the same. In this way a soft cushioning effect is obtained, and a similar effect is obtained upon outward movement of wall I0. Furthermore, before any substantial motion is imparted to the glass in one direction, the wall has reversed its direction and the movement of the glass in the rst direction is stopped. Since the wall vibrations are usually of small magnitude most of them occur while the glass panel is in the position where the mounting strip possesses maximum flexibility. The hollow rubber strip also provides a pneumatic cushion or yielding support for the relatively heavy pane of glass.

A modification of the ilexible window mounting is shown in Fig. 3 and comprises a soft rubber strip or seat 23 mounted between channel sides 24 with a narrow marginal portion 25 clamped between the sides of the narrower portion of the channel, as before.y 'I'he strip or member 23 comprises two hollow portions 26 between which is a slot adapted to receive the edge of window pane 2'I. At the base of said slot, there is a projecting portion or rib 28 on the rubber strip 23. The marginal portion of the window pane is cemented to' the side walls of the slot, but the edge of the pane is not cemented to projecting rib 28, the latter serving only to space the edge of the window pane from the base of the slot. In this construction the hollow portions 26 serve assoit cushions for the window pane, the operation being similar to that of the mounting shown in Fig. 2.

I claim:

1. A vibration dampening support for window panes comprising a window frame having a channel along the edges thereof, a flexible strip mounted between the sides of said channel, said flexible strip having an outwardly opening slot in which the edge of a window pane is held, the portions of said strip between said window pane and said channel sides being hollow.

2. A vibration dampening support for window panes comprising a window frame having a channel along the edges thereof, a flexible substantially tubular strip mounted in said channel, said strip having an outwardly opening slot formed in the circumference thereof, the edges of said window pane being held in said slot, the bottom wall of said slot cutting off communication between the interior of said tubular strip and said slot, whereby an air cushion is formed resistingvibration of the window pane in its own plane, and whereby lateral vibration of said window frame causes compression upon circumferential portions of said strip.

3. A vibration dampening support for window panes comprising a window frame having a channel along the edges thereof, a flexible substantially tubular stripmounted in said channel, the circumference of said strip having a reentrant portion extending into the hollow portion thereof and forming an outwardly opening slot, the edges of said window pane being heid in said slot.

4. A vibration dampening support for Window panes comprising a window frame having a channel along the edges thereof, a flexible strip mounted Within said channel and fastened to the base only of said channel, said flexible strip having an outwardly opening slot, the edges of said window pane being held in.said slot, the portions of said strip between said slot and the sides of said channel being hollow.

5. A vibration dampening support for window panes comprising a window frame having a channel along the edges thereof, said channel having a narrow base-portion and a relatively Wide outer portion, a flexible strip, said exible strip having a narrow edge portion clamped within the narrow portion of said channel and a relatively wide hollow portion held Within the wide portion of said channel, said hollow portion of said strip having an outwardly opening slot, said slot and the material surrounding the same extending inwardly into the hollow space of said strip, the edges of said window pane being held in said slot.

6. A vibration dampening support for window panes comprising a window frame having a channel along the edges thereof, a flexible 60 strip within said channel and fastened to the base portion of said channel, said flexible strip I having .an outwardly opening slot therein, the edge of said window pane being held in said slot, said strip having a hollow, substantially tubular portion on either side of said slot and between said slot and the side of said channel.

7. A vibration dampening support for window panes comprising a window frame having a channel along the edges thereof, flexible strip means almost wholly within said channel and fastened to the base portion of said channel, said strip means providing a slot extending inwardly between the side flanges of said channel for the reception of the edge of said window pane, said str ip means comprising hollow, substantially tubular portions on both sides of said slot and between said slot and said side flanges.

8.l As an article of manufacture, a flexible molded strip having a hollow body portion with a slot therein affording a seat for a sheet of transparent material, and having a narrow, solid vrib on the side opposite said slot, the hollowv part of said body extending around the walls of said slot from one side to the other, leaving thin side body walls joining the margins of said slotted walls, to permit ready flexing of the same as said transparent sheet material vlbrates.

9. A Window comprising a frame having a channel opening inwardly and a strip of flexible, compressiblelmaterial in said channel, the latter in section having a stepped arrangement of its side walls providing a flaring recess with substantially parallel marginal walls, said strip having a cross sectional configuration conforming to that of said channel and fitting closely within the same with no clearance along said marginal Walls and no adhesive therebetween, said strip having a slot to receive a pane of glass with the margin of said glass projecting between said marginal walls, and having a hollow portion between each side wall of said slot and the adjacent marginal wall, whereby lateral movement of said glass relatively to said frame compresses said tubular portions along one side or the other.

10. In .a window frame construction, a frame having a channel around the inside thereof, a rubber cushioning member fitted in said channel, said cushioning member having a slot therein to receive a pane of glass with the edge of said pane projecting into said channel but spaced therefrom, and having also a tubular passageway along each side of said slot, forming pneumatic buffers on opposite sides of the edge of said glass to cushion the lateral vibrations thereof.

l1. A window construction as in the preceding 

